Implications of Intrahepatic Cholangiocarcinoma Etiology on Recurrence and Prognosis after Curative-Intent Resection: a Multi-Institutional Study.

BACKGROUND: We sought to investigate the prognosis of patients following curative-intent surgery for intrahepatic cholangiocarcinoma (ICC) stratified by hepatitis B (HBV-ICC), hepatolithiasis (Stone-ICC), and no identifiable cause (conventional ICC) etiologic subtype.

METHODS: 986 patients with HBV-ICC (n = 201), stone-ICC (n = 103), and conventional ICC (n = 682) who underwent curative-intent resection were identified from a multi-institutional database. Propensity score matching (PSM) was used to mitigate residual bias.

RESULTS: HBV-ICC patients more often had cirrhosis, earlier stage tumors, a mass-forming lesion, well-to-moderate tumor differentiation, and an R0 resection versus stone-ICC or conventional ICC patients. Five-year recurrence-free survival among HBV-ICC and conventional ICC patients was 23.9 and 17.8%, respectively, versus a recurrence-free of only 8.3% among patients with stone-ICC. Similarly, 5-year overall survival among patients with stone-ICC was only 18.3% compared with 48.9 and 38.0% for patients with HBV-ICC and conventional ICC, respectively. On PSM, patients with stone-ICC group had equivalent long-term outcomes as HBV-ICC patients. In contrast, on PSM, stone-ICC patients had a median overall survival of only 18.0 months versus 44.0 months for patients with conventional ICC. Median overall survival after intrahepatic-only recurrence among patients who had stone-ICC (6.0 months) was worse than OS among HBV-ICC (13.0 months) or conventional ICC (12.0 months) (p = 0.006 and p = 0.082, respectively).

CONCLUSIONS: While HBV-ICC had a better prognosis on unadjusted analyses, these differences were mitigated on PSM suggesting no stage-for-stage differences in outcomes compared with stone-ICC or conventional ICC. In contrast, patients with stone-ICC had worse long-term outcomes. These data highlight the relative importance of ICC etiology relative to established clinicopathological factors in the prognosis of patients with ICC.